Rotary offset printing press with removable plate cylinder unit

ABSTRACT

There is disclosed in connection with an offset rotary printing press, means for inserting therein different diameters of plate cylinders, and as an assembly with each plate cylinder, form roller cam stop means for precisely spacing the form rollers with respect to each different diameter plate cylinder. In conjunction with the foregoing, a unique form roller actuating system is disclosed.

United States Patent 11 1 Christoff Nov. 27, 1973 [54] ROTARY OFFSET PRINTING PRESS WITH 3,259,060 7/1966 Martin 101 144 REMOVABLE PLATE CYLINDER UNIT 3,323,452 6/1967 Pasquinelli. 101/218 3,448,686 6/1969 Bohman 101/349 [75] Inventor: Chris A. Christoff, Lancaster, Calif.

[73] Assignee: Stevens Corporation, Fort Worth, P Exami'1er *Edgal' Tex. AttorneyPennie, Edmonds, Morton, Taylor and 22 Filed: July 15, 1970 Adams [21] App]. No.: 55,016 [57] ABSTRACT There is disclosed in connection with an offset rotary [52] [1.8. CI. 101/219, 101/218, 101/349 pr nting press, means for inserting therein different di- 51 Int. Cl. B411 5/04, B 4lf 7/02 meters of plate cylinders, and as an sem ly with [58] Field of Search ..l0l/141-145, 200, each plate cylinder, form roller cam stop means for 216-218, 247, 348-352 precisely spacing the form rollers with respect to each different diameter plate cylinder. In conjunction with [56] References Cited the foregoing, a unique form roller actuating system is UNITED STATES PATENTS dlsclosed- 2,660,113 11/1953 Gullixson et a1 101/350 3 Claims, 9 Drawing Figures PATENIEUNHVZHQH 3.774.537

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INVENTOR. cums IHRISTOFF BY w ATTORNEYS PATENTED NOV 2 7 I973 ROTARY OFFSET PRINTING PRESS WITH REMOVABLE PLATE CYLINDER UNIT BACKGROUND OF THE INVENTION U.S. Pat. No. 3,259,060 owned by the present Assignee, discloses certain improvements in offset rotary printing presses wherein an auxiliary frame adapted to be inserted into the main frame is provided, each auxiliary frame carrying a plate cylinder rotatably supported therein which may be of a different size from one previously inserted in the press. The apparatus of the patent further provided yieldable means for moving an ink form roller toward the plate cylinder when the auxiliary and main frames were secured together, the auxiliary frame carrying adjustable stop means for the form roller to limit the position of the form roller with respect to the newly inserted plate cylinder.

In the apparatus of the patent a four-position, stop means mounted in the press accommodated plate cylinders of four different diameters by controlling the precise positioning of three additional form rollers with respect to each plate cylinder. All of the form rollers were actuated separately by individual air cylinders.

It is the purpose of the present invention to improve upon the press described'in the above mentioned patent. The improvements herein enhance the manner of interchanging plate cylinders and provide a positive and simplified actuation system for form rollers.

SUMMARY OF THE INVENTION In accordance with the present invention, in combination with a rotary offset printing press, an auxiliary frame or insert is provided for rotatably supporting a plate cylinder, said frame having cam stop means for precisely positioning a plurality of form rollers carried by the pressrelative to said plate cylinder. The advantage of this arrangement is that auxiliary frames or inserts each carrying a different diameter plate cylinder can now be set up completely in advance of installation in a press, thus minimizing shutdown time. In combination with the foregoing, the invention provides a cable actuation system for effecting positive even movement of the form rollers toward or away from a plate cylinder. The new actuation system requires fewer motors to operate and takes less space in comparison with prior arrangements.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary sectional elevation view through a rotary offset printing press illustrating a particular embodiment of the present invention;

FIG. 2 is a transverse view of an auxiliary frame which can be inserted into the press of FIG. 1;

FIG. 3 is a side elevational view of the auxiliary frame as shown in FIG. 2; 1

FIG. 4 is a side view in section of the auxiliary frame of FIG. 3 showing the assembled position of cam stop plates; v

FIGS. Sa-Sd are details of cam stop plates shown assembled in FIG. 4; and

FIG. 6 is a perspective view of a fonn roller actuation system constructed according to the principles of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing and initially to FIGS. 1 and 2 thereof, there are illustrated portions of a rotary offset printing press 10 incorporating the apparatus of the I present invention. The press 10 includes a pair of spaced vertical side frames 11 and 12. Various web feeding, inking and guiding rollers are supported in bearings carried by the side frames. For details of one form of such press which are not shown or described in the present application, we refer to the aforementioned US. Pat. No. 3,259,060. I

A web 13 of paper or the like is continuously fed at a constant speed from a suitable supply source or from a preceeding printing station and proceeds around an adjustable compensating roller 14, over an impression cylinder 15 and under an idler roller 16 to either a succeeding printing station or to a delivery station (not shown) where the web may be cut into appropriate lengths or rewound onto a take-up roll. A blanket cylinder 17 carrying a rubber blanket 18 on its periphery engages the upper surface of the web as it passes around the impression cylinder to transfer an ink image from a plate cylinder 20 having a lithographic plate to the web in the usual manner.

A water dampening mechanism for the plate cylinder comprises a water foundation roll 21 rotatably mounted in bearings carried by the side frames. The roll 21 is partially immersed in a water tray 22 and is effective to transfer a film of water to water form roller 23 supported for free rotation at its opposite ends-in arms 23a which are pivotably connected to the shaft of foundation roll 21. The actuation of water form roller 23 may be seen in conjunction with FIGS. 1 and 6. Air cylinder 25 actuates plunger 26 to draw cables 27 downward. The cables 27 pass about a series of sheaves 45, 46 and are connected at opposite ends of water form roller 23 to arms 23a. Thus the roller 23 will be drawn against the plate cylinder 20 when cylinder 25- is operated. Form roller 23 will be swung away from plate cylinder 20 by gravity when cylinder 25 is deactuated.

Arranged in a series about the upper circumference of cylinder 20 are three ink form rollers 28, 29 and 30. Form rollers 28 and 29 are supported for swinging, pivotal movement on arms 28a, 29a which may rotate about the common shaft of vibrator roller 31. Form roller 30 is pivotally mounted on arm 30a which is rotatably mounted to the common shaft of vibrator roller 32. It will be understood that arranged above the ink form rollers 28-30, is an ink fountain ductor and distached thereto. Cables 36, 37 after passing under sheaves 38, 39 are anchored at their ends 36a, 37a to a bracket 40 secured in the press 10. Springs 41, 42 a provide a certain amount of resiliency to cables 36, 37. Cables 36, 37 pass over sheaves 43, 44. Cable 36 then passes around sheaves 45, 46 and thereafter engages firstly the end of the amt 30b of the arm 30a attached to ink form roller 30. Next, cable 36 passes around the end 28b of arm 28a of ink form roller 28 and finally is attached to the end 2% of arm 29a of ink form roller 29. It will be understood that cable 37 is in similar engagement with corresponding parts at the opposite In opposition to the movement of cables 36, 37, are two spring loaded cable return systems. The first of these indicated generally by reference numeral 50, comprises a pair of cables 51, 52 connected by a spring 55 respectively pass over sheaves 53, 54. The ends of cables 51 and 52 are connected as shown about a cylinderical end portions 32a attached to shaft 32b of vibrator roller 32. Consequently, cables 51, 52, by the action of spring 55 will oppose the rotation of arms 300 about shaft 3217 by cables 36 and 37.

Similarly, a second spring-loaded return cable system 56 having a spring 57 and center cable 58 connected to pulleys 59, 60 exerts opposition to movement of rollers 28, 29 by cables 36, 37. Spring return system 56 has cables 61, 62 at each end thereof which are fastened about the ends of arms 28a and 29b and are anchored at 63 to the shaft ends 63a of vibrating roller 61 in such manner as to oppose the action of cables 36 and 37. The action of the cylinder 34 when drawing cables 36, 37 is such that ink form rollers 28-30 are drawn into contact with the plate cylinder 20. Release by cylinder 34 permits cable return systems 50 and 56 to move the form rollers 28-30 away from the plate cylinder.

The invention provides in conjunction with the roller actuation system just described novel means for assuring the precise positioning of each form roller with respect to a plate cylinder of a given diameter.

Auxiliary frame or insert 65 can be inserted into the press 10 as a unit to provide for different diameters of plate cylinders 20. When the auxiliary frame 65 is secured in press 10, the side frames 66 and 67 are mated with and in effect become a unitary part of frames I1 and I2. Bolts 69 hold the auxiliary frame 65 securely in position. The plate cylinder installation 70 includes an external manually operated lever 71 for lateral adjustment of the plate cylinder. With reference to FIG. 4, it will be seen that the end support 72 for the shaft 17a of the blanket cylinder may be rotated by a bell crank 73 whose shaft 74 is rotatable by a lever 75. R- tation of the lever 75 will effect rotation of the eccentric support 72 to move the blanket cylinder into and out of contact with the plate cylinder.

In accordance with a further aspect of the present invention, a series of cam stop plates 76-79 which have been illustrated individually in FIGS. a-5d, are secured to the inner side of each of the frames 66 and 67 concentrically with respect to the axis of plate cylinder 20. Each of the plates 76-79 has a projecting cam stop 76a-79a. The plates are successively secured in overlying relation to each of frames 66, 67 by means of bolts 8083. Elongated slots 80a-82a are in the cam stop plates to receive the bolts 8082 which permit circumferential adjustment of the cam stop plates. Slots 83a are elongated radially to admit eccentric screws 83. Rotation of screws 83 will therefore shift the plate circumferentially and locking of screws 82 locks each plate circumferentially.

As will be seen in FIG. 4, the shafts 84, 85 and 86 of ink form rollers 28-30 and of water form roller 23 bear upon the sides of cam stops 76a-79a which therefore limit movement of the form rollers toward the plate cylinder 29. Precise positioning of each form roller can be accomplished even when the press is running by individual shifting of each plate 76-79 by first loosening screws 82 (screws 80 and 81 have spring washers which permit some relative movement in slots 80a, 81a) and then by rotating eccentric screws 83-until the plates 76-79 are each adjusted. Thereafter screws 82 are tightened. Furthermore, it will be seen that an infinite number of stop cam plates whose configurations vary from those illustrated can be mounted in each auxiliary frame to accommodate an infinite number of diameters of plate cylinders. The auxiliary frame 65 can therefore be completely set up in advance for insertion into a rotary press and once inserted therein the form rollers can be brought into contact with the plate cylinder (as limited by plates 76-79) without any adjustment of cam stops or other means carried by the press itself. When once a final adjustment of the cam stop plates has been made during running of the press, each auxiliary frame 65 can be stored in a unit together'with its specific plate cylinder. This will radically reduce down time of the press the next time the particular plate cylinder is used.

The infinitely variable cam stop system just described cooperates with the form roller actuation system to positively and precisely position the form rollers into contact with the plate cylinders of different diameters. The actuation system of the invention permits greater movement of the form rollers toward and away from the plate cylinder and therefore a press can accommodate a greater range of diameters of plate cylinders. Form roller actuation pressure to actuate all ink form rollers is applied from a single cylinder and thus pressure is more evenly distributed. Fewer actuators are needed. Since the cable actuation system is more compact laterally, minimum lateral space is required resulting in minimum journal length of all rollers in the press.

It will be understood that the above description has described a particular embodiment of the invention and is therefore representative. In order to appreciate fully the scope of the invention reference should be made to the appended claims.

WHAT IS CLAIMED IS:

1. In a rotary printing press, the combination comprising a main frame including a pair of spaced main side frame elements, said elements having means for locating an auxiliary frame in operative relation thereto, said auxiliary frame including a pair of spaced auxiliary side frame elements; means cooperating with said locating means for detachably securing said auxiliary frame elements and said main frame elements, a plate cylinder rotatably supported by said auxiliary frame, at least two form rollers, shaft means supporting said rollers in said main frame circumferentially about said plate cylinder, means for moving said form rollers into and out of engagement with said plate cylinder, a pair of stops for each form roller, the stops of each pair being mounted on said spaced auxiliary side frame element in positions to contact said roller shaft means and to locate each said form roller associated therewith precisely with respect to said plate cylinder carried by said auxiliary frame, and means for adjusting each stop of each pair of stops relative to and independent of said plate cylinder after said auxiliary frame is located in said main frame in operative relation to said press.

2. In a rotary printing press, the combination comprising a main frame including a pair of spaced main side frame elements; said elements having means for locating an auxiliary frame in operative relation thereto, said auxiliary frame including a pair of spaced auxiliary side frame elements; means cooperating with said locating means for detachably securing said auxiliary frame elements and said main frame elements, a

plate cylinder rotatably supported by said auxiliary frame, at least two form rollers, shaft means supporting said rollers in said main frame circumferentially about said plate cylinder, means for moving said form rollers into and out of engagement with said plate cylinder, stop means having separate cam stops for each of said form rollers, and adjusting means for attaching said stop means to said side auxiliary frame elements to position each of said cam stops in contact with one of said roller shaft means, and to limit movement of said form rollers toward said plate cylinder, said stop means comtron. 

1. In a rotary printing press, the combination comprising a main frame including a pair of spaced main side frame elements, said elements having means for locating an auxiliary frame in operative relation thereto, said auxiliary frame including a pair of spaced auxiliary side frame elements; means cooperating with said locating means for detachably securing said auxiliary frame elements and said main frame elements, a plate cylinder rotatably supported by said auxiliary frame, at least two form rollers, shaft means supporting said rollers in said main frame circumferentially about said plate cylinder, means for moving said form rollers into and out of engagement with said plate cylinder, a pair of stops for each form roller, the stops of each pair being mounted on said spaced auxiliary side frame element in positions to contact said roller shaft means and to locate each said form roller associated therewith precisely with respect to said plate cylinder carried by said auxiliary frame, and means for adjusting each stop of each pair of stops relative to and independent of said plate cylinder after said auxiliary frame is located in said main frame in operative relation to said press.
 2. In a rotary printing press, the combination comprising a main frame including a pair of spaced main side frame elements; said elements having means for locating an auxiliary frame in operative relation thereto, said auxiliary frame including a pair of spaced auxiliary side frame elements; means cooperating with said locating means for detachably securing said auxiliary frame elements and said main frame elements, a plate cylinder rotatably supported by said auxiliary frame, at least two form rollers, shaft means supporting said rollers in said main frame circumferentially about said plate cylinder, means for moving said form rollers into and out of engagement with said plate cylinder, stop means having separate cam stops for each of said form rollers, and adjusting means for attaching said stop means to said side auxiliary frame elements to position each of said cam stops in contact with one of said roller shaft means, and to limit movement of said form rollers toward said plate cylinder, said stop means comprising a plurality of individual plates each having a portion defining one of said cam stops, said plates being superimposed one upon the other, an array of said plates being arranged concentrically about the axis of said plate cylinder, said plates being individually adjustable in concentric directions about said axis.
 3. The combination according to claim 2 wherein said auxiliary frame defines access means permitting adjustments to each plate while the press is in operation. 